oooo!! wowwowowowow The illustrations posted throughout this thread are beautiful, gorgeous, magical!!! I think the best children's book illustrations (or any illustrations in that case) doesn't have to always be overly complicated, and spotted with every colour of the spectrum, but it's the ones that you can relate you, the ones that warm your heart, make you smile, and make you wish you were part of their world maybe just for one day. Yes, I know. I'm turning into a weak marshmallow, but I love my picture books; one of my most favourite books was "The tooth fairy" by Shirley Barber, :p the colours were just so pretty and soft, and her home was up in the clouds!!

A book I read some time ago was 'The Little Prince' ( Le Petit Prince) written and illustrated by Antoine de Saint Exupéry. I loved the story, and his drawings he did to accompany the story had a sort of childish edge to it, which fitted the story perfectly. The pictures are sort of like a really lovely sketch, not as polished around the edges; if that makes sense...
Well, this is the lovely prince I've been talking about
source: lookingglassreview.com

:p You just have to love it, right? The story seems to simple, but the much more complicated underlying meaning that comes through from the story really does make you feel all squishy and wonderful inside

I'm having trouble editing my previous post, just wanted to add that I got my picture of the Little Prince from the lookingglassreview.com